One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant sunflowers in Mankato can be determined by looking at the USDA zone info.

Planting Calendar for Sunflowers

Frost tolerance for sunflowers:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's not a good idea to plant sunflowers until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant sunflowers in Mankato is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant sunflowers and expect a good harvest is probably August. Any later than that and your sunflowers may not have a chance to fully mature. Starting your sunflowers indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Mankato. In the coldest months of winter you should expect an average low temperature of -25°F.

Since the USDA zone info for Mankato is just an average the actual date of last frost is different every year. Half of the time in Mankato you get surprised by a frost after May 15 so be sure to be ready to cover your sunflowers if you have a late frost.

USDA Zone Info for Mankato

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Mankato

You may be interested in your other planting guides for Mankato.